Surgical fastener deployment system

ABSTRACT

A deployment device and an associated surgical fastener as well as their methods of use are disclosed. In one embodiment, the deployment device includes a restraining mechanism constructed and arranged to temporarily limiting movement of a surgical fastener back span. The surgical fastener includes two legs extending in a distal direction from opposing ends of the back span. The legs are in a first closed position with a first shape. The deployment device also includes a spreader configured and arranged to engage the legs of the surgical fastener in the first closed position. When the spreader is moved in a distal direction relative to the back span, the spreader spreads the legs of the surgical fastener from the first closed position to a second open position as the back span is limited from distally moving by the restraining mechanism.

FIELD

Disclosed embodiments are related to surgical fastener deploymentsystems.

BACKGROUND

Surgical fasteners are widely used in many different medical procedures.For example, staples, sutures, clips and other fasteners are commonlyused in laparoscopic and open surgical procedures.

SUMMARY

In one embodiment, a deployment device includes a handle and anelongated shaft extending from the handle. At a distal end of the shaft,a restraining mechanism is constructed and arranged to temporarily limitdistal movement of a back span of a surgical fastener. The surgicalfastener includes two legs extending in a distal direction from opposingends of the back span and the legs have a first closed position with afirst shape. A spreader is configured and arranged to engage the legs ofthe surgical fastener in the first closed position. Moving the spreaderin a distal direction relative to the back span spreads the legs of thesurgical fastener from the first closed position to a second openposition as the back span is limited from moving distally by therestraining mechanism.

In another embodiment, a method for deploying a surgical fastenerincludes: providing a deployment device including a surgical fastener ata distal end of the deployment device; limiting distal movement of aback span of the surgical fastener, wherein the surgical fastenerincludes two legs extending in a distal direction from opposing ends ofthe back span, wherein the legs are in a first closed position with afirst shape; and pushing against an interior surface of the legs whilemovement of the back span is limited to spread the two legs to an openposition.

In yet another embodiment, a surgical fastener includes a back span andtwo legs extending in a distal direction from opposing ends of the backspan. The legs are in a first closed position with a first shape and areadapted to be opened to at least a straight orientation andautomatically return to the first shape.

In another embodiment, a surgical fastener includes a back span and twolegs extending in a distal direction from opposing ends of the backspan. The legs are in a first closed position with a first shape and theback span is located in a plane that is above a plane in which the legsare located.

It should be appreciated that the foregoing concepts, and additionalconcepts discussed below, may be arranged in any suitable combination,as the present disclosure is not limited in this respect. Further, otheradvantages and novel features of the present disclosure will becomeapparent from the following detailed description of various non-limitingembodiments when considered in conjunction with the accompanyingfigures.

BRIEF DESCRIPTION OF DRAWINGS

The accompanying drawings are not intended to be drawn to scale. In thedrawings, each identical or nearly identical component that isillustrated in various figures may be represented by a like numeral. Forpurposes of clarity, not every component may be labeled in everydrawing. In the drawings:

FIG. 1 is a schematic view of a surgical fastener deployment device;

FIG. 2 is an exploded schematic view of the distal end of the surgicalfastener deployment device;

FIG. 3A is a schematic perspective view of a surgical fastener and thedeployment mechanism prior to deployment;

FIG. 3B is a schematic perspective view of the surgical fastener anddeployment mechanism of FIG. 3A during a subsequent deployment step;

FIG. 3C is a schematic perspective view of the surgical fastener anddeployment mechanism of FIG. 3A during a subsequent deployment step;

FIG. 3D is a schematic perspective view of the surgical fastener anddeployment mechanism of FIG. 3A during a subsequent deployment step;

FIG. 3E is a schematic perspective view of the surgical fastener anddeployment mechanism of FIG. 3A during a subsequent deployment step;

FIG. 3F is a schematic perspective view of the surgical fastener anddeployment mechanism of FIG. 3A during a subsequent deployment step;

FIG. 4A is a schematic top view of a surgical fastener and thedeployment mechanism prior to deployment;

FIG. 4B is a schematic top view of the surgical fastener and deploymentmechanism of FIG. 4A during a subsequent deployment step;

FIG. 4C is a schematic top view of the surgical fastener and deploymentmechanism of FIG. 4A during a subsequent deployment step;

FIG. 4D is a schematic top view of the surgical fastener and deploymentmechanism of FIG. 4A during a subsequent deployment step;

FIG. 4E is a schematic top view of the surgical fastener and deploymentmechanism of FIG. 4A during a subsequent deployment step;

FIG. 4F is a schematic top view of the surgical fastener and deploymentmechanism of FIG. 4A during a subsequent deployment step;

FIG. 5A is a schematic side view of a surgical fastener and a deploymentmechanism prior to deployment;

FIG. 5B is a schematic side view of the surgical fastener and deploymentmechanism of FIG. 5A during a subsequent deployment step;

FIG. 5C is a schematic side view of the surgical fastener and deploymentmechanism of FIG. 5A during a subsequent deployment step;

FIG. 5D is a schematic side view of the surgical fastener and deploymentmechanism of FIG. 5A during a subsequent deployment step;

FIG. 5E is a schematic side view of the surgical fastener and deploymentmechanism of FIG. 5A during a subsequent deployment step;

FIG. 5F is a schematic side view of the surgical fastener and deploymentmechanism of FIG. 5A during a subsequent deployment step;

FIG. 6A is a schematic perspective view of a surgical fastener prior todeployment;

FIG. 6B is a schematic perspective view of the surgical fastener of FIG.6A during a subsequent deployment step;

FIG. 6C is a schematic perspective view of the surgical fastener of FIG.6A during a subsequent deployment step;

FIG. 6D is a schematic perspective view of the surgical fastener of FIG.6A during a subsequent deployment step;

FIG. 6E is a schematic perspective view of the surgical fastener of FIG.6A during a subsequent deployment step;

FIG. 7 is an exploded schematic perspective view of a deploymentmechanism;

FIG. 8 is a schematic perspective view of a deployment mechanism;

FIG. 9A is a schematic front view of a surgical fastener;

FIG. 9B is a schematic side view of the surgical fastener of FIG. 9A;

FIG. 9C is a schematic perspective view of the surgical fastener of FIG.9A;

FIG. 10A is a schematic perspective view of a surgical fastener anddeployment mechanism prior to deployment;

FIG. 10B is a schematic perspective view of the surgical fastener anddeployment mechanism of FIG. 10A during a subsequent deployment step;

FIG. 10C is a schematic perspective view of the surgical fastener anddeployment mechanism of FIG. 10A during a subsequent deployment step;

FIG. 10D is a schematic perspective view of the surgical fastener anddeployment mechanism of FIG. 10A during a subsequent deployment step;and

FIG. 10E is a schematic perspective view of the surgical fastener anddeployment mechanism of FIG. 10A during a subsequent deployment step.

DETAILED DESCRIPTION

The inventors have recognized the benefits associated with a surgicalfastener capable of being spread to an open state and returned to aclosed state using either superelasticity and/or shape memory effects.Since the surgical fasteners are capable of closing without the need tobe separately formed, an associated deployment device does not need toinclude a separate mechanism for closing the surgical fasteners. Thiscombination of a simplified deployment device and self-closing surgicalfasteners may offer quick deployment of surgical fasteners, reducedactuation forces, a smaller profile deployment mechanism, reduced cost,and improved ease of manufacturing.

In one embodiment, a surgical fastener includes a back span and a pairof legs extending from opposing ends of the back span. The pair of legsmay be shaped to overlap with one another along a portion of theirlengths and form a closed loop. The legs may either touch, or be spacedfrom one another. Depending on the particular embodiment, the legs maycurve to form a closed loop with a circular shape, though other shapesare also possible. One or more of the surgical fasteners may besequentially arranged on a retainer, or other appropriate carrier, andmay be sequentially provided to a deployment mechanism using anyappropriate feeding mechanism or fastener magazine arrangement. Once adistal most fastener is removed from the retainer, the closed loopformed by the pair of legs may be engaged by a corresponding spreaderand the back span may be held in place by an associated restrainingmechanism. While engaged with the pair of legs, the spreader may bemoved in a distal direction relative to the back span which isrestrained by the restraining mechanism. Since the legs are engaged withthe spreader and the back span is held by the restraining mechanism, therelative movement of the spreader and the back span of the surgicalfastener applies a distally directed force to the legs which spreads thelegs apart to an open position. As the legs are spread to the openposition, one or more guiding features on the spreader and/or othercomponents may be used to guide the legs to their desired positions forsubsequent deployment. In other embodiments, the restraining mechanismmay permit some distal movement of the back span while it is restrained.However, the spreader would still move distally relative to the backspan in such an embodiment. Further, it is this movement of the spreaderrelative to the back span that results in the distally directed forcebeing applied to the legs to spread them to the open position.

In addition to the spreader and the restraining mechanism, a pusher ispositioned to engage the back span of the distal most fastener. With thefastener in the opened position, the restraining mechanism releasesand/or permits the distal movement of the surgical fastener. The pusherthen distally displaces the fastener to deploy the spread legs intotissue. Depending on the particular embodiment, the legs of the surgicalfastener may be formed against an anvil or other appropriate feature asthe pusher displaces the surgical fastener in a distal direction furtherspreading the legs of the surgical fastener. Once the pusher has fullydeployed the surgical fastener, the back span of the surgical fasteneris released from the pusher.

The surgical fastener may be made from a material exhibitingsuperelasticity and/or shape memory properties. Therefore, as the pairof legs are inserted into tissue, the pair of legs either spring backfrom the open position to the original closed loop shape due tosuperelasticity or the surgical fastener is warmed and the pair of legsreturn to the original closed loop shape due to the noted shape memoryeffect. It should be understood that a combination of the two effectsmay also occur. Several nonlimiting examples of appropriate materialsexhibiting sufficient superelasticity and/or shape memory propertiesinclude super alloys such as nickel titanium alloys, iron nickel alloys,copper aluminum nickel alloys, and other appropriate bioresorbable ornon-absorbable metals. Additionally, in some embodiments, the surgicalfasteners may be made from a polymer exhibiting shape memory properties.In such an embodiment, the polymer may also be bioresorbable. Whilespecific materials are noted above, any material exhibiting sufficientsuperelasticity and/or shape memory properties could be used.

It should be understood that while in some embodiments the surgicalfasteners have a closed loop shape and overlapping legs as describedabove, the current disclosure is not so limited. Instead, in someembodiments the legs of the surgical fastener might not overlap and thesurgical fastener might have another shape. For example, the legs mightform a C shape, a U shape, or any other appropriate shape.Alternatively, the surgical fastener might still form a closed loop, butthe distal ends of the legs might be arranged end-to end such that theydo not overlap one another. In view of the above, it should beunderstood that the surgical fasteners may have any desired shape andconfiguration.

In some embodiments the surgical fasteners return to their initialclosed loop shape after being spread to the open position and deployedinto tissue. However, in some embodiments, the surgical fastener mayonly partly return to the closed loop shape due to forces being appliedto the legs of the surgical fastener from engaged tissue. Alternatively,some amount of unrecoverable permanent deformation of the surgicalfastener might occur. Therefore, it should be understood that thecurrent disclosure is meant to include embodiments in which the surgicalfastener returns to its initial closed loop shape as well as embodimentsin which the surgical fastener only partly returns to its initial closedloop shape. Further, in some embodiments the surgical fasteners mightreturn to a shape that is smaller than the initial closed loop shape.For example, the surgical fasteners might include an initial amount ofdeformation when they are positioned in the deployment position. Thesurgical fasteners can then be further spread to the open position andrecover to a shape smaller than the initial shape when they are deployedinto tissue using a superelastic and/or shape memory effect. In otherembodiments, the fastener may transform from an open shape to a finalshape that is not closed.

The surgical fasteners may have any desired dimensions appropriate fortheir intended application. However, in one embodiment the surgicalfasteners have a width that is between about 2 mm to 3 mm, 3 mm to 4 mm,4 mm to 5 mm, or any other appropriate width. The surgical fastener mayalso include sufficient superelasticity and/or shape memory propertiesto fully recover from being spread to an open width between about theoriginal width of the surgical fastener and 1 mm, 2 mm, 3 mm, 4, mm, or5 mm wider than the original width of the surgical fastener or any otherappropriate length. Both larger and smaller dimensions for the initialwidth of the fastener as well as the width of the open position arepossible.

In addition to the surgical fasteners, the various components of thedeployment device may also be made from any appropriate material orcombination of materials including various appropriate metals andpolymers. Appropriate materials include, but are not limited to:stainless steels such as 316L stainless steel; nickel titanium basedalloys such as nitinol; polypropylene; high density polyurethane;ultrahigh molecular weight polyethylene (UHMWPE); nylon; polyester; orany other appropriate material.

For the sake of clarity, the currently disclosed embodiments aredirected to a laparoscopic device. However, the current disclosure isnot limited to laparoscopic devices. Instead, the currently disclosedsurgical fasteners and associated deployment devices could be used inany appropriate device for the deployment of a surgical fastener intotissue. For example, any of the currently disclosed components, orcombination of disclosed components, could be incorporated into anendoscopic device, a borescopic device, a catheter, a deployment devicefor use in “open” procedures, or any other appropriate deploymentdevice. Additionally, the deployment device may be loaded with one ormore fasteners prior to being provided to an end user, or it may beconstructed to allow the user to load the instrument with one or morefasteners.

For the sake of clarity, the figures do not depict a feeding mechanismassociated with the plurality of surgical fasteners. However, it shouldbe understood that any appropriate feeding mechanism could be used tosequentially provide a plurality of surgical fasteners to the deploymentmechanism. For example, a walking beam structure in which areciprocating mechanism sequentially displaces either a stack ofsurgical fasteners or individually displaces each surgical fastener in astack of surgical fasteners towards a deployment position could be used.Alternatively, a spring applying a distally directed force could be usedto bias a stack of surgical fasteners towards a deployment position.Additionally, any appropriate mechanism capable of positioning thedistal most surgical fastener in the deployment position might be used.Appropriate mechanisms can include springs, tabs, gravity assistedpositioning, or any other mechanism or method capable of positioning thedistal most surgical fastener in the deployment position. In view of theabove, it should be understood that the feeding mechanism associatedwith the disclosed surgical fasteners and deployment device can beembodied in any number of different ways and the current disclosure isnot limited in this fashion.

It should also be understood, that the various components describedbelow in reference to the figures such as the spreader, pusher, former,anvil, and various guide structures can also be embodied in any numberof different ways. Therefore, the current disclosure should not belimited to only the embodiments depicted in the figures and describedherein.

Turning now to the figures, specific embodiments are described in moredetail. However, it should be understood, that embodiments differentfrom those depicted in the figures are also possible.

FIG. 1 depicts a deployment device 2 in the form of a laparoscopicinstrument for deploying one or more surgical fasteners into aprosthetic and/or tissue. The deployment device 2 includes a handle 4 ata proximal end of the device and a trigger 6. The deployment device alsoincludes an elongated shaft 8 extending in a distal direction from thehandle 4. When the trigger 6 is actuated, a surgical fastener isdeployed from a distal tip of the elongated shaft 8. It should beunderstood, that the deployed surgical fastener may be deployed into anyappropriate prosthetic, tissue, or other target. A prosthetic may beembodied by any number of different components or materials. Forexample, in one embodiment, the prosthetic may be a soft tissue repairfabric, such as a surgical mesh, and used for repairing a hernia.

One specific embodiment of a deployment device is depicted in FIG. 2which shows an exploded view of the various components disposed at thedistal end of an elongated shaft 8. These components include a former10, a spreader 18, and a pusher 24 as well as a cover 16 for coveringthose portions of these components that extend past a distal end of theelongated shaft 8. As described in more detail below, these componentsare used to deploy one or more surgical fasteners 28 from the distal endof the elongated shaft 8.

In the depicted embodiment, the surgical fastener 28 in a closedposition includes a straight back span 28 a and a pair of legs 28 bextending in a distal direction from opposing ends of the back span. Thepair of legs 28 b are curved inwards and overlap each other for at leasta portion of their lengths. The legs 28 b include pointed tips that areadapted to pierce through an intended tissue and/or prosthetic.Additionally, in the depicted embodiment, the back span 28 a is locatedin a plane that is above the plane in which the legs 28 b are locatedin. Therefore, the legs 28 b include a bend where they are joined to theback span 28 a. While the legs 28 b are depicted as touching oneanother, they may also be spaced apart from one another in someembodiments. Further, while the back span 28 a has been depicted asbeing straight, other shapes including a curved back span, a back spanincluding one or more bends, or other appropriate features might beused.

The former 10 includes one or more guide surfaces 12, a ramp 14, and ananvil 16 that collectively guide and form the surgical fastener duringdeployment. As depicted in the figure, the one or more guide surfaces 12include a proximally located portion that slopes upwards towards adistally extending flat surface that extends up to the anvil 16. Asdescribed in more detail below, the sloped portion and the distallyextending flat surface of the guide surfaces 12 help to guide the legs28 b of the surgical fastener 28 towards the anvil 16 as the legs of thesurgical fastener are spread to the open position. Similar to the guidesurfaces 12, the anvil 16 also guides the legs 28 b of the surgicalfastener during deployment. Specifically, the anvil 16 defines twooutwardly oriented grooves that the legs 28 b are pressed against inorder to spread the legs to a width that is greater than a width of theoriginal closed loop shape of the surgical fastener. In some embodimentsthe width that the anvil 16 spreads the legs 28 b to is greater than awidth of the elongated shaft 8. Unlike the one or more guide surfaces 12and the anvil 16 which interact with the legs 28 b of the surgicalfastener, the ramp 14 is constructed and arranged to interact with theback span 28 a of the surgical fastener in order to release the surgicalfastener 28 at the end of deployment. As depicted in the figure, theramp 14 includes raised portions 14 a positioned above the anvil 16 andon opposing sides of a cutout 14 b for accommodating distal movement ofthe pusher 24. The raised portions 14 a are constructed and arranged topermit the back span 28 a of the surgical fastener to cam over theraised portions of the ramp as it is deployed from the distal end of theelongated shaft. While specific constructions of the guide surfaces 12,the ramp 14, and the anvil 16 are depicted in the figure and describedabove, other alternative constructions are also possible.

The spreader 18 applies a force to an interior surface of the legs 28 bof the surgical fasteners, spreading the legs to an open position. Thespreader 18 includes a distal end 22, a groove 20, and an overhang 21,as shown in FIG. 2. More specifically, the distal end 22 is sized andshaped to engage with the interior surface of the legs 28 b of thesurgical fastener. While a rounded shape that complements a shape of thelegs has been depicted, other shapes not complementing a shape of thelegs, including a flat surface, might be used. The spreader 18 alsoincludes a groove 20 that extends around the distal end 22 and along aportion of the sides of the spreader 18. The groove 20 is sized andshaped to accommodate the legs 28 b of the surgical fastener. Therefore,as the spreader 18 spreads the legs 28 b to the open position, the legswill become positioned in the groove 20 which may help to guide andposition the legs for subsequent deployment. An overhang 21 extendsdistally outwards and is located above the distal end 22 of thespreader, though other arrangements are also possible. Therefore, whenthe surgical fastener 28 is positioned with the pair of legs 28 blocated below the overhang 21, the overhang 21 retains the legs 28 b onthe spreader 18 during spreading by preventing upwards movement of thelegs 28 b off of the distal end 22.

A slot 26 located at a distal end of the pusher is sized and shaped toreceive the back span 28 a of the surgical fastener. With the back span28 a of the surgical fastener retained in the slot 26 of the pusher, andthe pusher 24 held stationary, distal movement of the back span 28 awithin the elongated shaft 8 is prevented when the spreader 18 advancesagainst the legs 28 b. In addition, when the pusher 24 is moved in adistal direction, the slot 26 will apply a distally directed force tothe back span 28 a to distally displace and deploy the surgical fastener28. While a slot has been depicted, other appropriate features and/orseparate components are contemplated to restrain and/or push thesurgical fastener. For example, the slot might be replaced by hooks,posts, or other appropriate features.

FIGS. 3A-5F illustrate the deployment device and the surgical fastenerduring different stages of deployment. A wall of the former is removedin FIGS. 3A-3F for visualization purposes. The shape of the surgicalfastener during these different stages of deployment are illustrated inFIGS. 6A-6E.

As depicted in these figures, the spreader 18 is disposed on the formerand the pusher 24 is disposed on top of the spreader 18. Prior toactuation, a distal most surgical fastener 28 is positioned in aninitial deployment position with its back span 28 a disposed in the slot26 of the pusher 24 which is located in a plane above the upper surfaceof the spreader, see FIGS. 3A, 4A, 5A, and 6A. The pair of legs 28 b arealso engaged with the distal end 22 of the spreader. In this initialposition, the distal most surgical fastener 28 is still in its initialclosed loop shape.

During the initial stages of actuation, the spreader 18 is moved in adistal direction while the pusher 24 is held stationary, see FIGS. 3B,3C, 4B, 4C, 5B, and 5C. As the spreader 18 moves in the distal directionrelative to the pusher, the distal end 22 of the spreader applies adistally directed force to the interior surfaces of the legs 28 b of thesurgical fastener. Since the back span 28 a of the surgical fastener isheld stationary by the pusher 24, the distally directed force spreadsthe legs 28 b towards an open position. The groove 22 may be located inthe same plane as the anvil 16. Therefore, as the legs 28 are spread,groove 22 helps to guide the legs 28 b towards the anvil 16. Similarly,as the legs are spread, the guide surfaces 12 on the former 10 also helpto guide the legs 28 b up the sloped proximal portion of the guidesurfaces 12 and onto the distally extending flat surfaces towards theanvil 16. As the distal movement of the spreader 18 continues, the legs28 b of the surgical fastener are spread from the closed loop initialshape to an open position where the legs are straight, though other openconfigurations of the legs are also possible. The partially openedposition and the fully opened position of the legs 28 b are depicted inFIGS. 6B and 6C. After opening the legs 28 b to the fully openedposition, distal movement of the spreader 18 continues until it contactsa proximal surface of the ramp 14. However, distal movement of thespreader 18 could be stopped at any point after the legs of the surgicalfastener have been opened in other embodiments.

Once the legs 28 b of the surgical fastener have been spread to the openposition, the pusher 24 is moved in a distal direction. Since the backspan 28 a of the surgical fastener is positioned in the slot 26 of thepusher, the pusher 24 applies a distally directed force to the back span28 a and the surgical fastener is displaced in the distal direction. Asthe surgical fastener is moved in the distal direction, the back span 28a is displaced in a plane above the spreader 18. The legs 28 b aredisplaced along the guide surfaces 12 of the former and are retained atleast partially in the groove 22 of the spreader in order to guide thelegs towards the anvil 16 and maintain them in the open position, seeFIGS. 3D, 4D, 5D, and 6D.

As distal movement of the pusher 24 continues, the distal ends of thelegs 28 b contact the anvil 16. The anvil 16 is constructed and arrangedsuch that the legs 28 b are pressed against the anvil and displacedoutwards as the surgical fastener is moved in the distal direction. Incertain embodiments, the anvil is constructed and arranged such that thelegs are displaced to a width that is greater than a width of theinitial closed loop shape of the surgical fastener. Further, in someinstances this width may be greater than a width of the elongated shaftthat the surgical fasteners are disposed within.

As distal movement of the pusher 24 continues, the pusher 24 enters thecut out 14 b located in the ramp and the back span 28 a of the surgicalfastener cams over the raised portions 14 a of the ramp. As the backspan 28 a of the surgical fastener is displaced upwards out of the slot26, the surgical fastener is released from the deployment device, seeFIGS. 3F, 4F, and 5F. As noted above, as the surgical fastener 28 isdeployed into tissue, the legs 28 b return towards the initial closedloop shape due to either superelasticity or a shape memory property ofthe surgical fastener, see FIG. 6E. After the surgical fastener has beendeployed, the pusher 24 and the spreader 18 are retracted to theirinitial positions and the next surgical fastener is positioned in thedeployment position for subsequent deployment.

FIGS. 7-10E are directed to another embodiment of a deployment device.FIGS. 7 and 8 best illustrate the components of this deployment deviceand their relative arrangements. Similar to the above embodiment, thedeployment device includes a former 10, a spreader 18, and a pusher 26.However, in this embodiment, the deployment device includes a separatedeflectable hook 40 that acts as a restraining mechanism for selectivelypreventing distal movement of a surgical fastener 28. The deploymentdevice also includes an extendable cannula 32 that is biased towards aretracted position by an associated return spring 42.

As depicted in the figures, the surgical fastener 28 again includes aback span 28 a and a pair of legs 28 b extending in a distal directionfrom opposing ends of the back span. The legs are also curved inwardsand overlap each other for at least a portion of their lengths, seeFIGS. 7-9C. However, unlike the previous embodiment, the back span 28 ais located in, or just slightly above, the same plane in which the legswill be deployed. Therefore, the legs 28 b do not include a downwardsbend at their connection with the back span 28 a. Without wishing to bebound by theory, by arranging the back span 28 a in the same plane inwhich the legs will be deployed, a force can be applied to the surgicalfastener without an associated moment being applied to the surgicalfastener which may help to avoid rotation and misalignment of thesurgical fastener during deployment. The surgical fastener 28 alsoincludes a distally extending dimple 28 c located at a midpoint of theback span 28 a which helps to position the surgical fastener 28 on thedeflectable hook 40 and may help to prevent tilting and/or rotation ofthe surgical fastener while it is held thereon.

The former 10 may be fixed relative to the elongated shaft. The former10 includes an anvil 16 that is constructed and arranged to form thesurgical fastener into a straight open configuration as compared tospreading the legs further apart as in the previous embodiment. Theformer 10 also includes a round depression 36 shaped to accommodate asurgical fastener corresponding to an initial deployment position of adistal most surgical fastener.

The spreader 18 includes a distal end 22 constructed and arranged toengage the legs 28 b of the surgical fastener to spread them to an openposition. However, in this embodiment, the distal end 22 is a flatsurface and the grooves 20 for guiding the surgical fastener duringopening and deployment do not wrap around the distal end of the spreaderand instead only extend proximally from the distal end along the sidesof the spreader 18. It should be understood that a spreader with adifferent shape at the distal end and/or a different arrangement of thegrove might be used. For example, a spreader including a rounded distalend and/or a groove that extends around the distal end similar to thatdescribed above is contemplated. The spreader 18 also includes twooverhangs 21 that extend distally along the upper side edges of thespreader 18 for retaining the surgical fastener 28 during deployment.The overhang 21 again retains the surgical fastener 28 by preventing theupward movement of the legs 28 b of the surgical fastener until theyhave been moved to the open position. The spreader 18 also includes acamming surface 38 adapted to move the restraining mechanism between anopen and restraining position. As depicted in the figures, the cammingsurface 38 extends along a portion of an upper surface of the spreader18 in a proximal direction from the distal end 22 of the spreader. Aslot 48 passes through the upper and lower surfaces of the spreader 18and is elongated in the axial direction.

The pusher 24 includes a slot 26 located on a distal face of the pusher.The slot 26 is sized and shaped to engage the back span 28 a of thesurgical fastener and prevents vertical displacement of the back spanwhile they are engaged. Due to the slot 26 being located on the distalface of the pusher, the pusher 24 does not act as a restrainingmechanism against distal movement of the surgical fastener back span inthis embodiment.

In this embodiment, the restraining mechanism for selectively preventingdistal movement of the surgical fastener back span 28 a is provided bythe deflectable hook 40. As described in more detail below, the use of adeflectable hook to selectively prevent the distal movement of thesurgical fastener back span 28 a permits the use of a back span 28 alocated in substantially the same plane in which the legs are deployed.As illustrated in figures, the deflectable hook 40 includes two fingers44 that are sized and positioned to engage the back span 28 a of thesurgical fastener on either side of the dimple 28 c. It should beunderstood that while two fingers have been shown, any number fingerscould be used. The deflectable hook 40 is biased downwards such that itcams against the camming surface 38 on the spreader 18 in order toselectively control restraint of the surgical fastener during deploymentas described in more detail below. The deflectable hook 40 also includesa post 46 which is sized and shaped to pass through the slot 48 of thespreader 18 while permitting distal movement of the spreader duringactuation.

An extendable cannula 32 includes two partial cannula 34 located at adistal end of an elongated beam 33. During actuation, the partialcannulas 34 are extended out of the deployment device and into adjacenttissue. The partial cannula 34 are sized and shaped to accommodate thelegs 28 b of the surgical fastener. Since the legs 28 b of the surgicalfastener are attached to the back span 28 a, the partial cannulas 34include open sides to permit the legs to pass there through while theback span is able to pass over them. Without wishing to be bound bytheory, the extendable cannula 32 may help to avoid buckling of thesurgical fastener as it is inserted into a prosthetic and/or tissuesince it guides the surgical fastener during the initial insertion intothe tissue. The extendable cannula 32 may also result in better tissuebite and depth of purchase as well as a straighter deployment. The useof an extendable cannula may be of particular benefit when the surgicalfasteners are deployed in harder tissues and/or through dense prostheticmaterials though this embodiment could be used with any appropriatetissue and/or prosthetic. With appropriate modifications to controldeployment of the individual cannulas in different angled directionscorresponding to the anvil's shape, the concept of extendable cannulasto help guide the surgical fastener as it is deployed into tissue couldalso be used with the embodiment described above with regards to FIGS.2-6E.

The relative positioning of the above components for deploying asurgical fastener are illustrated in FIG. 8. An elongated beam 33 of theextendable cannula 32 is movably attached to a bottom surface of theformer 10 at the distal end of the deployment device in such a way thatit is able to move in a distal direction. When assembled with the former10, the partial cannula 34 are aligned with the grooves of the anvil 16.As noted above, the return spring 42, not depicted in this figure, isattached to the extendable cannula 32 and the former 10, or othercomponent, to bias the extendable cannula in a proximal direction. Thespreader 18 is also disposed on the former 10 and has a distal end 22positioned in an initial deployment position. The deflectable hook 40 isdisposed on the spreader 18 and is fixedly mounted relative to theformer 10 such that it is does not move in the distal direction. Abottom surface of the deflectable hook 40 is biased against the cammingsurface 38 of the spreader 18, with the post 46 positioned in the slot48 of the spreader. The post 46 and slot 48 are both constructed andarranged to permit distal movement of the spreader 18 while thedeflectable hook remains fixed in position. The pusher 24 is disposed ontop of the deflectable hook 40 and is also movable in a distal directionrelative to the former 10.

In FIGS. 10A-10E which depict the deployment device and the surgicalfastener during different stages of deployment. Prior to actuation, adistal most surgical fastener 28 is positioned in an initial deploymentposition 36 of the former 10, see FIG. 10A. Additionally, the extendablecannula 32, spreader 18, and pusher 24 are positioned in retractedproximal positions. A back span 28 a of the surgical fastener isretained by the fingers 44 of the deflectable hook 40. As depicted inthese figures, the dimple 28 c of the surgical fastener is locatedbetween the fingers 44 which may help to prevent rotation andmisalignment of the surgical fastener 28 when retained by thedeflectable hook 40. The legs 28 b of the surgical fastener are engagedby the distal end 22 of the spreader 18. The slot 26 located on thedistal face of the pusher 24 is engaged with the back span 28 a of thesurgical fastener and may help to prevent vertical movement of the backspan relative to the pusher during deployment.

With the surgical fastener in the initial deployment position 36, thedeployment device is actuated and the spreader 18 is moved in a distaldirection, see FIG. 10B. Applying a distally directed force to the legs28 b of the surgical fastener. Simultaneously, the deflectable hook 40is held in the restraining position by the camming surface 38.Consequently, as the back span 28 a is held stationary, the distallydirected force deforms the legs 28 b towards the open position. The legs28 b are pressed against the grooves of anvil 16 to a straight openposition. Additionally, the overhangs 21 and the grooves 20 of thespreader 18 maintain the legs 28 b of the surgical fastener in the openposition. Distal movement of the spreader 18 continues with the spreader18 applying a distally directed force to the extendable cannula 32, seeFIG. 10C, causing the partial cannulas 34 to extend out of a distal endof the deployment device and into an adjacent tissue and/or prosthetic.As the spreader is moved in the distal direction, the camming surface 38of the spreader is displaced past the deflectable hook 40 allowing thedeflectable hook 40 to move to the open position and release the backspan 28 a of the surgical fastener, see FIG. 10D. Further distaldisplacement of the pusher 24 forces the back span 28 b of the surgicalfastener down the shaft. As the surgical fastener 28 is distallydisplaced by the pusher 24, the legs 28 b pass through the grooves ofanvil 16 and into the partial cannulas 34 of the extendable cannula 32.As noted above, the partial cannulas 34 are open on their exteriorfaces. Therefore, as the legs 28 b of the surgical fastener pass throughthe partial cannulas and into the adjacent tissue and/or prosthetic, theback span 28 a of the surgical fastener is able to pass above thepartial cannulas 34. Distal displacement of the pusher 24 continuesuntil it has reached its distal most position and the surgical fasteneris released from the deployment device, see FIG. 10E. Similar to theprior embodiment, as the surgical fastener 28 is deployed into tissue,the legs 28 b return towards the initial closed loop shape due to eithersuperelasticity or a shape memory property of the surgical fastener. Itshould be noted that in the current embodiment, the back span 28 a isdisplaced along a single plane and is not cammed in a vertical orhorizontal direction in order to release the surgical fastener. However,embodiments in which the surgical fastener 28 is cammed to release itfrom the deployment device are also possible.

After the surgical fastener has been deployed, the spreader 18 andpusher 24 are retracted in the proximal direction. In response to thespreader retracting, the extendable cannula 32 is also retracted in theproximal direction by the associated return spring, not depicted. Thedeflectable hook 40 is then cammed upwards to the retaining position asthe camming surface 38 of the spreader engages the lower surface of thedeflectable hook 40. Once each of these components are positioned forthe next actuation, the next distal most surgical fastener is positionedfor deployment.

While the present teachings have been described in conjunction withvarious embodiments and examples, it is not intended that the presentteachings be limited to such embodiments or examples. On the contrary,the present teachings encompass various alternatives, modifications, andequivalents, as will be appreciated by those of skill in the art.Accordingly, the foregoing description and drawings are by way ofexample only.

What is claimed is:
 1. A deployment device comprising: a handle; anelongated shaft extending from the handle, at a distal portion of theshaft: a restraint that temporarily limits distal movement of a backspan of a surgical fastener, the surgical fastener including two legsextending in a distal direction from opposing ends of the back span,wherein the legs have a first closed position with a first shape; aspreader that engages the legs of the surgical fastener in the firstclosed position, wherein moving the spreader in a distal directionrelative to the back span spreads the legs of the surgical fastener fromthe first closed position to a second open position as the back span islimited from moving distally by the restraint; and an anvil, wherein asthe surgical fastener is deployed in a distal direction, the legs areformed against the anvil, and wherein the anvil forms the legs to asecond shape with a width that is larger than a width of the firstshape.
 2. The deployment device of claim 1, wherein the restrainttemporarily prevents distal movement of the back span.
 3. The deploymentdevice of claim 1, wherein the first shape is a closed loop.
 4. Thedeployment device of claim 1, wherein the restraint releases the backspan after the spreader spreads the legs of the surgical fastener to theopen position.
 5. The deployment device of claim 1, wherein therestraint comprises a hook that temporarily prevents movement of theback span.
 6. The deployment device of claim 1, further comprising apusher that pushes the back span of the surgical fastener in a distaldirection to deploy the surgical fastener.
 7. The deployment device ofclaim 6, wherein the restraint is the pusher.
 8. The deployment deviceof claim 1, further comprising a ramp that engages the back span torelease the surgical fastener during deployment.
 9. The deploymentdevice of claim 1, wherein the spreader includes one or more groovesthat guide the legs of the fastener as the spreader is moved in thedistal direction.
 10. The deployment device of claim 1, furthercomprising the surgical fastener.
 11. The deployment device of claim 1,wherein the restraint engages the back span in a first plane, and thespreader engages the legs in a second plane different from the firstplane.
 12. A deployment device comprising: a surgical fastener; ahandle; an elongated shaft extending from the handle, at a distalportion of the shaft: a restraint that engages a back span of thesurgical fastener to temporarily limit distal movement of the back span,the surgical fastener including two legs extending in a distal directionfrom opposing ends of the back span, wherein the legs have a firstclosed position with a first shape; and a spreader configured andarranged to engage the legs of the surgical fastener in the first closedposition, wherein moving the spreader in a distal direction relative tothe back span spreads the legs of the surgical fastener from the firstclosed position to a second open position as the back span is limitedfrom moving distally by the restraint, wherein the restraint engages theback span in a first plane and the spreader engages the legs in a secondplane different from the first plane.
 13. The deployment device of claim12, wherein the restraint is disposed on the spreader.
 14. Thedeployment device of claim 12, wherein the restraint temporarilyprevents distal movement of the back span.
 15. The deployment device ofclaim 12, wherein the first shape is a closed loop.
 16. The deploymentdevice of claim 12, wherein the restraint releases the back span afterthe spreader spreads the legs of the surgical fastener to the openposition.
 17. The deployment device of claim 16, wherein the spreaderincludes a camming surface that controls the restraint.
 18. Thedeployment device claim 12, wherein the restraint comprises adeflectable hook that temporarily prevents movement of the back span.19. The deployment device of claim 12, further comprising a pusher thatpushes the back span of the surgical fastener in a distal direction todeploy the system of surgical fastener.
 20. The deployment device ofclaim 19, wherein the restraint is the pusher.
 21. The deployment deviceof claim 12, further comprising a ramp that engages the back span torelease the surgical fastener during deployment.
 22. The deploymentdevice of claim 12, further comprising an anvil, wherein as the surgicalfastener is deployed, the legs are formed against the anvil.
 23. Thedeployment device of claim 22, wherein the anvil forms the legs to asecond shape with a width that is larger than a width of the firstshape.
 24. The deployment device of claim 12, wherein the spreaderincludes one or more grooves that guide the legs of the fastener as thespreader is moved in the distal direction.
 25. The deployment device ofclaim 12, further comprising cannulas that guide the legs of thesurgical fastener as they are deployed.
 26. The deployment device ofclaim 25, wherein the cannulas are selectively extendable from a distalend of the deployment device.
 27. The deployment device of claim 25,wherein the cannulas have open sides.
 28. The deployment device of claim27, wherein the open sides of the cannulas permit the legs to passthrough the cannulas and the back span to pass over the cannulas. 29.The deployment device of claim 28, wherein the open sides of thecannulas permit the legs to pass through the cannulas and the back spanto pass over the cannulas.
 30. The deployment device of claim 29,wherein the restraint is disposed on the spreader.
 31. A deploymentdevice comprising: a surgical fastener; a handle; an elongated shaftextending from the handle, at a distal portion of the shaft: a restraintthat temporarily limits distal movement of a back span of the surgicalfastener, the surgical fastener including two legs extending in a distaldirection from opposing ends of the back span, wherein the legs have afirst closed position with a first shape; a spreader that engages thelegs of the surgical fastener in the first closed position, whereinmoving the spreader in a distal direction relative to the back spanspreads the legs of the surgical fastener from the first closed positionto a second open position as the back span is limited from movingdistally by the restraint; and an anvil, wherein as the surgicalfastener is deployed the legs are formed against the anvil, and whereinthe anvil forms the legs to a second shape with a width that is largerthan a width of the first shape.
 32. The deployment device of claim 31,wherein the restraint temporarily prevents distal movement of the backspan.
 33. The deployment device of claim 31, wherein the first shape isa closed loop.
 34. The deployment device of claim 31, wherein therestraint releases the back span after the spreader spreads the legs ofthe surgical fastener to the open position.
 35. The deployment device ofclaim 31, further comprising a pusher that pushes the back span of thesurgical fastener in a distal direction to deploy the surgical fastener.36. The deployment device of claim 35, wherein the restraint is thepusher.